1. Field of Invention
This invention relates to a color dot recorder, and more particularly to such a recorder wherein a multicolored ribbon is used to record analog data in the form of a plurality of dots of different colors and to record various characters and symbols in one or more arbitrary colors.
2. Discussion of the Prior Art
A conventional dot color recorder is known, such as disclosed in U.S. Pat. No. 4,433,338 and shown in FIG. 1, and comprises an inked ribbon unit 10, an inked ribbon 11 having a plurality of lengthwise extending different color channels arranged in a side by side relation, an inked ribbon cassette 12 in which is housed the inked ribbon 11, a plurality of wire hammer units 20 arranged in the direction of movement of a carriage (not shown) and each in opposing relation with each color channel of the inked ribbon 11, a wire hammer 21 which is a component of each wire hammer unit 20, a driving mechanism 22 for selectively driving wire hammers 21 in response to recording signals, a recording sheet 30, and a platen 40. Ribbon unit 10 and wire hammer units 20 are mounted on the carriage (not shown) in such a way that wire hammers 21 are in opposing relation with recording sheet 30 through inked ribbon 11.
In the conventional color dot recorder, the carriage reciprocates over the effective recording width including zero and span of recording sheet 30 in a direction perpendicular to the direction of feed of sheet 30, and is stopped at a position corresponding to the magnitude of a recording signal. While the carriage remains stationary, wire hammers 21 are selectively driven in response to the recording signals so that the corresponding color channels of ribbon 11 are pressed against sheet 30 and consequently color dots are recorded. In response to the driving of wire hammers 21, ribbon 11 is moved at a predetermined rate in the direction of feed of sheet 30, and sheet 30 is moved by a predetermined length generally when the carriage is reversed in direction and is maintained stationary when the carriage does not reach the point where the direction of movement of the carriage is reversed.
FIG. 2 shows the relationship between ribbon 11 and wire hammers 11 of the conventional dot recorder. Wire hammers 21.sub.1 -21.sub.6 are disposed in the direction of movement of carriage indicated by a double pointed arrow A in opposing relation to the different color channels or strips C.sub.1 -C.sub.6, respectively, of ribbon 11. That is there is one wire hammer for each color strip.
The conventional color dot recorder has many disadvantages and deficiencies. For example, ribbon unit 10 and hammer unit 20 are mounted on the carriage so that the number of components is large. Consequently, the conventional color dot recorder is expensive.
Furthermore, the plurality of hammer units 20 are disposed in the direction of movement of the carriage so that the effective recording width of the sheet 30 is relatively narrow. Thus, with conventional color dot recorders, the total width for the recorder itself must be wider than the width desired of the recording sheet. Consequently, conventional color dot recorders are not very compact size.
Moreover, the conventional carriage is heavy in weight so that a relatively large, high powered motor must be used in order to move the carriage at high speeds. Thus, power consumption is large and considerable heat must be removed. Furthermore, since the carriage is heavy, a blinded sector, caused by insufficient rigidity of a driving string and by insufficient torque of a driving motor, results in a poor recording quality.
Also, the operation of the recorder itself is not satisfactory because when the ribbon cassette is replaced it must be displaced in the direction of movement of the wire hammers.
Furthermore, the carriage is relatively large in size and is caused to reciprocate over the recording sheet and hence it is difficult to read the results immediately after recording.
Finally, even though the measured results and alarm settings are displayed on a digital display, it is difficult to readily determine at a glance the relationship therebetween.